ML20078S668
| ML20078S668 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 12/15/1994 |
| From: | Mcmeekin T DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9412290113 | |
| Download: ML20078S668 (5) | |
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,e DuksIbwer Company T.C AlcVerxn kicGuire Nuclear Generation Department Vice President 12700Hagers ferryRoad(AIG0lVP)
(704)8754800 fluntemalle. NC280784985 (704)8754809 Fax DUKEPOWER December 15,1994 U.S Nuclear Regulatory Commission Document Control Desk Washington, D.C.
20555
Subject:
McGuire Nuclear Station Docket Nos. 50-369 and 50-370 Exception Taken to Examination Techniques Prescribed in ASME Section XI, Appendix III.
Gentlemen:
Duke Power Company Procedure NDE-600, revision 4 " Ultrasonic Examination of similar Metal Welds in Wrought Ferritic and Austenitic Piping" was qualified using test specimens fabricated in accordance with ASME Section XI, appendix VIII,1992 Edition with the 1993 Addenda. Essential variables used in the qualification were incorporated into the next revision (rev. 5).
Under the rules of ASME Section XI, Appendix III,111-111(d),1986 and 1989 Editions, alternate examination techniques are being used which differ from the ultrasonic methodology prescribed in Appendix Ill. In using these alternative techniques, Duke Power Company has taken exception to requirements of Appendix III that are listed in the attached letter dated August 26,1994.
If there are any questions regarding this issue, contact Dwin Caldwell at (704) 875-4328.
Very truly yours, T. C. McMeekin xc:
Mr. S. D. Ebneter Regional Administrator, Region II U. S. Nuclear Regulatory Commission 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 l
Mr. Victor Nerses U. S. Nuclear Regulatory Commission Ofnce of Nuclear Reactor Regulation One White Flint North, Mail Stop 9H3 Washington, D. C.
20555 Mr. George Maxwell Senior Resident Inspector McGuire Nuclear Station 1
9412290113 941215
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J. E. Snyder Ec050-ELL J. J. McArdle III 1
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- Gary Underwooi Dwin Caldwell Ray Pettit i
Subject:
Demonstration i Procedure NDE-600, Revision 4 Duke Power Company Procedure NDE-600, Revision 4, " Ultrasonic Examination of Similar Metal. Welds in Wrought Ferritic and Austenitic i
Piping" was qualified by performance demonstration at the EPRI NDE Center.
Test specimens used in the qualification were fabricated in accordance with ASME Section XI, Appendix Vill,1992 Edition with the 1993 Addenda.
Essential variables used in the qualification were incorporated into the next revision (Rev. 5).
Under the rules of ASME Section XI, Appendix lil,111-1100 (d),1986 and 1989 Editions, alternate examination techniques are being used which differ from the ultrasonic methodology prescribed in Appendix ill. In using these alternative techniques, Duke Power Company has taken exception to the following i
requirements of Appendix lil:
l 111-2120 The search unit sizes liste" a the procedure are based on nominal pipe size instead of pipe wall thickness.
Ill-2430 Sensitivity is based on setting a 5% to 10% noise level from the inside surface of the pipe to be examined.
j lll3210 Basic calibration blocks are not used for system calibration, therefore temperature requirements of this section are not applicable.
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lil-3230(a) The procedure qualification has demonstrated that coverage of the examination volume from two directions is not necessary to find flaws in the volume of interest.
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Page 2 of 3 lil-3230(b), (c), (d), (e) Basic calibration blocks are not used for system calibration, therefore the remainder of this section is not applicable.
Ill-3320 Calibration confirmation establishing the Distance-Amplitude-Correction (DAC) curve is not applicable.
111-3330 Since examination sensitivity is set on each pipe, the system check consists of verifying only the sweep range.
111-3400 Basic calibration blocks are not required. However, an Appendix ill basic calibration block is an option for beam angle measurement and screen distance calibration.
lll-3500 The following calibration data is not applicable:
- 1. Basic calibration block identification; l
- 2. Amplitudes and sweep readings from calibration reflectors.
lll-4410 The procedure qualification has demonstrated that a 60 beam angle is sensitive to ID connected flaws, while supressing the reflections from ID geometry such as counterbore. Therefore, a 60 angle is used as the primary angle for circumferentially 1
oriented flaws and a 45 angle is used for axially oriented flaws.
When the ID/OD ratio does not permit the use of a 45 angle, a refracted angle is selected that will produce an incident angle at the inside surface of 60. A 70 angle is used for flaw confirmation l
and to extend the coverage.
lll-4420 The procedure qualification has demonstrated that coverage of the examination volume from two directions to find circumferential flaws is not necessary. Scanning from two directions for axial flaws is addressed in the procedure.
111-4510 Since no DAC is used, recording of indications is based on signal amplitude as a % of full screen height (FSH) and the examiners use of discrimination techniques as detailed in paragraph 10.0 of the procedure.
lll-4520 Recorded indications are plotted on a cross sectional sketch.
Reflector end points are determined by setting the peak amplitude to 80% FSH and moving the search unit parallel to the reflector until the amplitude equals 20% FSH.
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i Page 3 of 3 Supplement 4-Beam angle measurements in austenitic pipe using refracted longitudinal waves are impractical because of mode conversion at the pipe inside surface. An ID reflector at a known location, such as a notch would be required to make this measurement.
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A James ). McArdle lli NDE Levellil UT NDE Technical Support I
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